Pressure and temperature relief valve and diaphragm valve

ABSTRACT

A temperature and pressure responsive relief valve assembly preferably used in the cooling system of an internal combustion engine to control the rate of flow of a coolant fluid through the engine, which valve assembly comprises a housing having an inlet and an outlet, and a fluid passageway interconnecting the inlet and the outlet and including a valve seat, a pressure responsive diaphragm valve in the passageway and including a peripheral edge fixed to the housing and an annular combination valve member and valve seat defining an opening and forming a portion of the passageway and movable relative to the valve seat and movable toward the outlet in response to fluid pressure the inlet, a thermostat mounted in the passageway and including a valve member movable in response to operation of the thermostat, and a spring in the passageway for biasing the combination valve member and valve seat into a seated position on the valve seat and on the valve member, and a second spring for biasing the valve member into a seated position on the combination valve member and valve sent.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to pressure and temperature relief valvearrangements and, more particularly, to pressure and temperature reliefvalve arrangements for restricting coolant flow through a water cooledinternal combustion engine. The invention also relates to a pressureresponsive diaphragm valve for use in the valve arrangement.

2. Reference to Prior Art

Numerous valve arrangements have been employed for use in the coolingsystems of internal combustion engines. Conventional temperature andpressure relief valve assemblies which are used in engine coolingsystems and which restrict coolant flow through the engine include twoseparate and independent valve members which seat on separate valveseats. One of the valve members is generally temperature responsive, andthe other of the valve members is generally operable in response to highfluid pressure in the cooling system caused by high engine speeds andthe resulting high coolant flow rate. The temperature responsive valveis commonly actuated by a thermostat comprising a body enclosing athermally responsive material, and a rod and piston arrangement whichmoves in response to expansion or contraction of the thermallyresponsive material. The pressure setting it which the pressureresponsive valve unseats is commonly determined by compressing a biasingspring for the valve to a desired degree. The thermally responsive valvemember is also commonly biased into a seated position by a spring.

Conventional valve arrangements commonly employ valves and valve seatsmade of metal. The use of metal valves and valve seats can lead tocorrosion of the valve components.

Attention is directed to the following United Sates Patents:

    ______________________________________                                        U.S. Pat. No.                                                                              Inventor      Issued                                             ______________________________________                                        1,972,170    Spencer       September 4, 1934                                  2,497,201    Banner        February 4, 1950                                   2,570,432    Dillon        October 9, 1951                                    2,740,586    Chaniot       April 3, 1956                                      2,785,861    Kimm et al.   March 19, 1957                                     2,810,527    Work          October 22, 1957                                   3,498,537    Backman Wong  March 3, 1970                                      3,512,710    Resta         May 19, 1970                                       3,700,166    Foults        October 24, 1972                                   3,724,753    Thornton      April 3, 1973                                      4,078,722    Luckenball    March 14, 1978                                     4,344,564    Magnuson      August 17, 1982                                    ______________________________________                                    

SUMMARY OF THE INVENTION

The invention provides a temperature and pressure responsive reliefvalve assembly comprising a housing including an inlet and an outlet,and a fluid passageway in the housing interconnecting the inlet and theoutlet and including a first valve seat, a pressure responsive flexiblemember in the passageway and including a peripheral edge fixed to thehousing and an annular combination first valve member and second valveseat defining an opening forming a portion of the passageway and beingmovable relative to the first valve seat, a thermally responsiveassembly movably mounted in the passageway and including a thermallyresponsive actuator and a second valve member movable in response tooperation of the actuator and relative to the combined first valvemember and second valve seat for seating engagement between said secondvalve member and said combined first valve member and second valve seat,and means in the passageway for biasing the combined first valve memberand second valve seat into engaged position on the first valve seat andon the second valve member.

The invention also provides a diaphragm valve for use in a pressurerelief valve assembly including a housing having an inlet and an outlet,and a fluid passageway in the housing interconnecting the inlet and theoutlet and including an outer valve seat, and an inner valve seatmounted in the passageway, the diaphragm valve comprising a flexiblediaphragm adapted to be located within the passageway and includingperipheral edge adapted to be fixed to the housing, an annular valvemember on the flexible diaphragm and defining an opening forming aportion of the passageway and being movable relative to the outer valveseat and to the inner valve seat for seating engagement therewith.

In one embodiment, the diaphragm and pressure responsive valve memberare integral and are made of a non-metallic material.

A principal feature of the invention is the provision of a temperatureand pressure responsive relief valve assembly preferably used forautomatically controlling coolant flow in a water cooled internalcombustion engine, the temperature and pressure responsive valve membersserving as valve seats for each other.

Another principal feature of the invention is the provision of a reliefvalve arrangement which is self-cleaning and which will remove dirt anddebris from the valve seat of the thermally responsive valve member byrevving the engine.

Another principal feature of the invention is the provision of atemperature and pressure responsive valve assembly which resistscorrosion.

Still another principle feature of the invention is the provision of atemperature and pressure responsive valve assembly which provides adifferent size valve assembly for use in different size engines byinterchanging only one part.

Other feature and advantages of the invention will become apparent tothose skilled in the art upon review of the following detaileddescription, claims, and drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram, partially in section, illustratingvarious of the features of the invention as applied to the coolingsystem of an internal combustion engine.

FIG. 2 is a perspective view, partially in section, of a diaphragm valveembodying various of the features of the invention.

FIG. 3 is an enlarged schematic view, partially in section, of the valveassembly shown in FIG. 1, and showing the valves in closed positions.

FIG. 4 is a view similar to FIG. 3, and showing the temperatureresponsive valve member in an unseated position in response to highinlet fluid temperature conditions.

FIG. 5 is a view similar to FIG. 3, and showing the pressure responsivevalve member in an unseated position in response to high inlet fluidpressure conditions.

Before one embodiment of the invention is explained in detail, it is tobe understood that the invention is not limited in its application tothe details of the construction and the arrangements of components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is to be understood that thephraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting.

GENERAL DESCRIPTION

A pressure and temperature responsive relief valve assembly 10 embodyingvarious features of the invention is illustrated in the drawings. Whilethe valve assembly 10 can be used in various systems, machines orapparatus, in the illustrated arrangement, the valve assembly 10 is usedin the cooling system of an internal combustion engine to control therate of flow of coolant fluid through the engine. As will be seen fromthe following, the valve assembly 10 illustrated in the drawings isintended to automatically control coolant flow through the engine toachieve engine operating temperature within a desired temperature range.

Shown in FIG. 1 of the drawings is a portion of a water or coolantcooled, two-cycle internal combustion engine 12 which includes acylinder block 14, a cylinder head 16 fixed to the cylinder block 14, afluid or coolant passageway 18 extending through the cylinder block 14and the cylinder head 16, and the valve assembly 10 located in thepassageway 8. As is conventional, the engine 12 also includes a cylinderbore 20 containing a piston 22, the piston being connected to a crankshaft 24 through a rod 26 and a crank arm 28.

In the specific arrangement shown in the drawings, the cylinder head 16serves as a frame or housing for the valve assembly 10, and receives adownstream frame or housing member 32. As illustrated in the drawings,the housing member 32 is located upstream of the valve assembly 10 andincludes an annular valve sent or stop 34 and an inwardly directedannular flange 36 defining a fluid inlet 38. The cylinder head 16includes a cover portion 40 which is removably attached to the rest ofthe cylinder head 16 so that access can be gained to the valve assembly10. The cover 40 is attached by screws 42 or other conventional means.

Components of the valve assembly 10 include a pressure responsiveflexible member which in the illustrated arrangement is in the form of adiaphragm 44 and which includes an annular pressure responsive valvemember 46, and a temperature responsive assembly 48 including atemperature responsive valve member 50. Each of the valve members 46 and50 serve as valve seats for each other.

As shown in FIG. 2, the diaphragm 44 also includes an outer orperipheral edge 52 which is fixed to the cylinder head 16, and a rollingor bellows portion 58.

While the pressure responsive valve member 46 can be a separate memberattached to the diaphragm 44, in the illustrated arrangement, the valvemember 46 is integral with the diaphragm 44. The annular Pressureresponsive valve member 46 defines an opening 54 which forms part of thefluid passageway 18. The valve member 46 is moveable toward a fluidoutlet 64 in response to increased fluid pressure at the inlet 38, andis selectively engageable with both the valve seat 34 and thetemperature responsive valve member 50 to restrict fluid flow throughthe valve assembly 10. Fluid pressure is generally raised by increasingthe speed of the engine, since at higher engine speeds a water orcoolant pump (not shown) delivers more coolant to the engine 12.

The valve assembly 10 is provided with means for biasing the pressureresponsive valve member 46 into a seated position on the valve seat 34and on the temperature responsive valve member 50. While various meanscan be employed for biasing the pressure responsive valve 46, in theillustrated construction, the means for biasing includes a helicalspring 72 which has a first end bearing against the cover 40 and asecond end bearing against the pressure responsive valve member 46. Thespring 72 is rated to allow the valve member 46 to open at a desiredpredetermined fluid pressure. Preferably, the spring 72 will maintainthe valve member 60 on the valve seat 34 when the engine is operating atidle speeds and will allow the valve member 46 to unseat at enginespeeds in excess of idle speed.

The temperature responsive assembly 48 is mounted in the passageway 18.While various temperature responsive assemblies can be employed, in theillustrated arrangement, the temperature responsive assembly 48 is inthe form of a conventional thermostat which includes a thermostat body82, a pin 84 disposed partially within the body 82, and the temperatureresponsive valve member 50. The valve member 50 is selectivelyengageable with the pressure responsive valve member 46 to restrictfluid flow through the valve assembly 10. As is conventional, the body82 contains a thermally responsive expansible-contractable material (notshown) and serves as an actuator for the temperature responsive valvemember 50.

The valve assembly 10 is also provided with means for supporting thethermally responsive assembly 48 in the passageway 18. While varioussupporting means can be employed, in the illustrated construction, thesupporting means include a second helical spring 86 which includes afirst end bearing against the flange 36 and a second end bearing againstthe valve member 50. The spring 86 serves the dual purpose of biasingthe valve member 50 into a seated position on the pressure responsivevalve member 46, and forcing the pin 84 to bearing against the cover 40.The spring 86 is relatively stronger than the spring 72 to prevent thespring 72 from forcing the pin 84 out of engagement with the cover 40.

Typically, the thermostat body 82, the pin 84, and the temperatureresponsive valve member 50 are made of metal. Although the diaphragm 44and the pressure responsive valve member 46 can be made of any suitablematerial, non-metallic materials, such as rubber, are preferred. Meansare provided for isolating the metal components of the valve assembly 10from the metal components of the cylinder head 16. While other isolatingmeans can be employed, in the illustrated construction, the isolatingmeans includes an isolator 90 which is made of a non-metallic material.The cover 40 may itself be non-metallic, so that the separate isolator90 is not needed. The housing member 32 is also preferably made of anon-metallic material such as plastic. The use of non-metallic materialsfor the isolator 90 or cover 40, the pressure responsive valve member46, and the housing member 32 serves to isolate the metal thermostatcomponents from other parts made of metal, thereby tending to reduce oreliminate electrolytic corrosion. Furthermore, the use of non-metallicmaterials such as rubber aids in the reduction of corrosion and wearcaused by the vibration of components in contact with one another.

As can been seen from the drawings, the valve assembly 10 or componentsthereof can be easily removed from the cylinder head 16 after firstremoving the cover 40 from the cylinder head 16. In addition, the valveassembly 10 can be in the form of a complete drop-in unit which caninclude the housing member 32 and the isolator 90. The parts comprisingthe valve assembly 10, or the entire valve assembly 10, may be replacedwhen warn or defective.

The valve assembly 10 can be used in engines of all sizes by changing asingle part, such as the diaphragm 44. For example, when the valveassembly 10 is used in larger engines requiring greater coolant flowrates, or smaller engines requiring lesser coolant flow rates, the valvemember 46 of diaphragm 44 can be reduced or enlarged, respectively.Changing the size of the valve member 46 is accompanied by a change inthe size of the opening 54 which is defined by the valve member 46. Aspreviously mentioned, the opening 54 forms part of the passageway 18, sothat enlargement or reduction of the opening 54 allows greater or lessercoolant flow rates through the valve assembly 10.

An advantage of the valve assembly 10 is that it can be sized tomaximize the speed of the coolant flowing through the valve assemblywhile still maintaining a flow rate to properly cool the engine. Highercoolant flow speeds assist in flushing debris past the valve assembly10. The sizes of the pressure and temperature responsive valve members46 and 50 can be selected to maximize the speed of coolant flow aroundthe valve members and through the opening 54 while still allowing acoolant flow rate sufficient to cool the engine.

FIG. 3 illustrates the valve assembly 10 which is closed and which isoperating at inlet fluid pressure and temperature levels below thatrequired to open the valve assembly 10. The valve assembly 10 isprovided with means for purging air in the system. While various purgingmeans can be employed, in the disclosed construction, the purging meansincludes an orifice 94 which is located in the bellows portion 58 of thediaphragm 44 so that diaphragm flexure prevents mineral build-up in theorifice. Preferably, the valve assembly 10 remains closed at engine idlespeeds when the engine is cold.

FIG. 4 shows the temperature responsive valve member 50 in an openposition in response to increased inlet fluid temperature. As the engine12 warms up, increased fluid temperatures cause the thermally responsivematerial contained with the thermostat body 82 to expand which in turncauses the valve member 50 to move relative to the pressure responsivevalve member 46 and against the force of the spring 86 to permit fluidflow in the direction shown by the arrows in FIG. 4. When the engine isshut off or when the fluid flow rate is high enough to prevent thecoolant from becoming sufficiently warmed, the thermally responsivematerial will contract and the spring 86 will bias the thermallyresponsive valve member 50 toward the pressure responsive valve 46.

Referring to FIG. 5, the valve assembly 10 is shown acting under inletfluid pressure levels sufficient to move the pressure responsive valvemember 46 against the force of the spring 72 and away from the valveseat 34 and the temperature responsive valve member 50. As engine speedis reduced and fluid pressure decreases, the spring 72 biases thepressure responsive valve 46 back towards a seated position on the valveseat 34 and on the temperature responsive valve member 50.

Foreign matter which clogs the valve assembly 10 can cause poor engineperformance. For example, a chip of foreign matter may become lodgedbetween the valve members 46 and 50 so that the valve members do notproperly seal when engaging one another. When the engine is started, thechip may cause undesireable fluid leakage through the valve assembly 10.The increased fluid flow caused by the leakage can slow warm-up of theengine and can lead to engine difficulties such as rough idle.

Because the temperature responsive valve member 50 seats on the pressureresponsive valve member 46, dirt or debris can be flushed from the valveassembly 10 without movement of the temperature responsive valve member50. To remove a foreign substance lodged between the valve members 46and 50, the engine can be revved to increase engine speed so thatincreased fluid pressure at the inlet 38 causes the pressure responsivevalve member 46 to open so that the dirt or debris from between thevalve members 46 and 50 is flushed out.

Various features of the invention are set forth in the following claims.

I claim:
 1. A temperature and pressure responsive relief valve assemblycomprising a housing including an inlet and an outlet, and a fluidpassageway in said housing interconnecting said inlet and said outletand including a valve stop, a pressure responsive flexible member insaid passageway and including a peripheral edge fixed to said housingand an annular combination first valve member and valve seat defining anopening forming a portion of said passageway and being movable relativeto said valve stop, a thermally responsive assembly movably mounted insaid passageway and including a thermally responsive actuator and asecond valve member movable in response to operation of said actuatorand relative to said combined first valve member and valve seat forseating engagement between stud second valve member and said combinedrim valve member and valve seal and means in said passageway for biasingsaid combined first valve member and valve seat into engaged position onsaid valve stop and on said second valve member.
 2. A relief valveassembly as set fourth in claim 1, wherein said combined first valvemember and valve seat is made of non-metallic material.
 3. A reliefvalve assembly as set forth in claim 2, wherein said flexible membercomprises a diaphragm and wherein said thermally responsive actuatorextends through said opening.
 4. A relief valve assembly as forth inclaim 3, wherein said combined first valve member and valve seat isintegral with said flexible member.
 5. A relief valve assembly as setforth in claim 1, wherein said flexible member is made of a non-metallicmaterial.
 6. A relief valve assembly as set forth in claim 1, whereinsaid housing includes a top portion and another portion and means forremovably fastening said top portion to said other portion of saidhousing.
 7. A relief valve assembly as set forth in claim 1, whereinsaid flexible member has therein an orifice.
 8. A relief valve assemblyas set forth in claim 1, and further comprising means in said passagewayfor biasing said second valve member into a seated position on saidcombined first valve member and valve set.
 9. A relief valve assembly uset forth in claim 8, wherein said means for biasing said second valvemember has greater relative strength than said means for biasing saidcombined first valve member and valve seat.
 10. A diaphragm valve foruse in a pressure relief valve assembly including a housing having aninlet and an outlet, and a fluid passageway in the housinginter-connecting the inlet and the outlet and including an outer valve.[.stop.]. .Iadd.seat.Iaddend., and an inner valve seat mounted in thepassageway, said diaphragm valve comprising a flexible diaphragm adaptedto be located within the passageway and including a peripheral edgeadapted to be fixed to the housing, and an annular valve member on saidflexible diaphragm and defining an opening forming a portion of thepassageway and being movable relative to said outer valve .[.stop.]..Iadd.seat .Iaddend.and to said inner valve seat for seating engagementtherewith.
 11. A diaphragm valve as set forth in claim 10, wherein saiddiaphragm valve includes an integral valve member.
 12. A diaphragm valveas set forth in claim 10 wherein said valve member is made of anon-metallic material.
 13. A diaphragm valve as set forth in claim 10,wherein said valve member has therein an orifice.
 14. A diaphragm valveas set forth in claim 10, wherein said inner valve sent is movablerelative to said valve member and to said outer valve stop in responseto changes in the temperature of fluid in said passageway.
 15. Adiaphragm valve as set forth in claim 14 and further comprising memberfor biasing said valve member toward said outer valve stop and saidinner valve seat, and means for biasing said inner valve seat towardsaid valve member.
 16. A temperature and pressure responsive reliefvalve assembly comprising a housing including an inlet and an outlet,and a fluid passageway in said housing interconnecting said inlet andsaid outlet and including a valve stop, a pressure responsive flexiblemember in said passageway and including a peripheral edge fixed to saidhousing and an annular combination first valve member and valve seatdefining an opening forming a portion of said passageway and beingmovable relative to said valve stop, a thermally responsive assemblymovably mounted in said passageway and including a thermally responsiveactuator extending through said opening and a second valve membermovable in response to operation of said actuator and relative to saidcombined first valve member and valve seat for seating engagementbetween said second valve member and said combined first valve memberand valve seat, means in said passageway for biasing said combined firstvalve member and valve seat into engaged position on said valve stop andon said second valve member, and means in said passageway for biasingsaid second valve member into a seated position on said combined firstvalve member and valve seat.
 17. A relief valve assembly as set forth inclaim 16, wherein said means for biasing said second valve member hasgreater relative strength than said means for biasing said combinedfirst valve member and valve seat.
 18. A relief valve assembly as setforth in claim 16, wherein said combined first valve member and valveseat is integral with said flexible member. .Iadd.
 19. An engineincluding a metallic body defining a coolant passage, a temperatureresponsive valve assembly comprising a metallic part and including athermostatic body including a temperature responsive valve member, and apin extending from said thermostatic body, and means for supporting saidtemperature responsive valve assembly in said passage and forelectrically isolating said metallic part of said temperature responsivevalve assembly from said metallic body, said means includingnon-metallic means engaging said metallic body and said pin, andnon-metallic means engaging said metallic body and said thermostaticbody. .Iaddend. .Iadd.
 20. An engine in accordance with claim 19 whereinsaid non-metallic means engaging said pin comprises a metallic coverremovably connected to said metallic body and non-metallic isolatorbetween said cover and said pin. .Iaddend. .Iadd.
 21. An engine inaccordance with claim 19 wherein said non-metallic means engaging saidpin comprises a non-metallic cover removably connected to said metallicbody and engaging said pin. .Iaddend. .Iadd.
 22. An engine in accordancewith claim 19 wherein said non-metallic means engaging said thermostaticbody comprises a non-metallic member located in said passage. .Iaddend..Iadd.
 23. An engine including a metallic body defining a coolantpassage, a temperature responsive valve assembly including a metallicpart, a thermostatic body, and a pin extending from said thermostaticbody, means for supporting said temperature responsive valve assembly insaid passage and for electrically isolating said metallic part of saidtemperature responsive valve assembly from said metallic body, and anon-metallic pressure responsive member supported by said metallic body,extending across said passage, and including therein an openingaffording coolant flow therethrough, wherein said metallic body definingsaid coolant passage comprises a metallic cylinder head and a removablemetallic cover, wherein said temperature responsive valve assembly isselectively sealingly engagable with said pressure responsive valvemember to open and close said opening, and wherein said means forsupporting said temperature responsive valve assembly and forelectrically isolating said metallic part from said metallic bodycomprises a non-metallic housing member located in said passageway andengaging said metallic body and including therein a coolant inletcommunicating with said opening, a helical spring engaged between saidnon-metallic housing and said thermostatic body, and a non-metallicisolator located between said pin and said cover. .Iaddend. .Iadd.24. Anengine including a metallic body defining a coolant passage, atemperature responsive valve assembly including a metallic part, meansfor supporting said temperature responsive valve assembly in saidpassage and for electrically isolating said metallic part of saidtemperature responsive valve assembly from said metallic body, and anon-metallic pressure responsive member supported by said metallic body,extending across said passage, and including therein an openingaffording coolant flow therethrough, wherein said metallic body definingsaid coolant passage comprises a metallic cylinder head, wherein saidtemperature responsive valve assembly is selectively sealingly engagablewith said pressure responsive member to open and close said opening, andwherein said means for supporting said temperature responsive valveassembly and for electrically isolating said metallic part from saidmetallic body comprises a non-metallic housing member located in saidpassageway and engaging said metallic body and including therein acoolant inlet communicating with said opening, a helical spring engagedbetween said non-metallic housing and said thermostatic body, and anon-metallic cover located between said pin and said cylinder head..Iaddend.